1. Field of the Invention
The present invention relates to novel crystalline forms of a biphenyl compound, which are expected to be useful for treating pulmonary disorders. The invention also relates to pharmaceutical compositions comprising the crystalline compounds or prepared from such compounds, processes and intermediates for preparing such crystalline compounds and methods of using such compounds to treat a pulmonary disorder.
2. State of the Art
U.S. Patent Publication No. 2005/0203133 to Mammen et al. discloses novel biphenyl compounds that are expected to be useful for treating pulmonary disorders such as chronic obstructive pulmonary disease (COPD) and asthma. In particular, the compound biphenyl-2-ylcarbamic acid 1-(2-{[4-(4-carbamoylpiperidin-1-ylmethyl) benzoyl]methylamino}ethyl)piperidin-4-yl ester is specifically described in this application as possessing muscarinic receptor antagonist or anticholinergic activity.
The chemical structure of biphenyl-2-ylcarbamic acid 1-(2-{[4-(4-carbamoyl piperidin-1-ylmethyl)benzoyl]methylamino}ethyl)piperidin-4-yl ester is represented by formula I:
The compound of formula I has been named using the commercially-available AutoNom software (MDL, San Leandro, Calif.).
Therapeutic agents useful for treating pulmonary or respiratory disorders are advantageously administered directly into the respiratory tract by inhalation. In this regard, several types of pharmaceutical inhalation devices have been developed for administering therapeutic agents by inhalation including dry powder inhalers (DPI), metered-dose inhalers (MDI) and nebulizer inhalers. When preparing pharmaceutical compositions and formulations for use in such devices, it is highly desirable to have a crystalline form of the therapeutic agent that is neither hygroscopic nor deliquescent and which has a relatively high melting point thereby allowing the material to be micronized without significant decomposition. Although crystalline freebase forms of the compound of formula I have been reported in U.S. Patent Publication No. 2007/0112027 to Axt et al. as Form I and Form II, the crystalline freebase forms of the present invention have different and particularly useful properties, including higher melting points.